The present patent application relates to design and manufacturing of a class of high-performance battery and supercapacitor (referred as a super battery in the whole context of patent). With the rapid development of industrialization and the global economy, worldwide energy consumption has increased steadily, which inevitably leads to the increasing depletion of fossil fuels and deterioration of the environment.
Exploring renewable energy sources (such as solar, wind and tidal energy), and also improving efficiency of energy use, for example, the use of electric or hybrid electric vehicles to replace the traditional internal combustion engine vehicles, have become the main strategy to solve the energy crisis.
Therefore, to develop easy, stable electrochemical energy storage devices with fast power delivery capability becomes increasingly urgent. Facing this challenge, sustainable, low pollution electrochemical energy storage devices will be the core technology for supporting modern civilization.
Batteries and supercapacitors are commonly used electrochemical devices for portable electronics, electric vehicles, renewable energy storage, and other applications. Commonly referred electrochemical energy devices mainly include lead-acid batteries, nickel-cadmium (Ni—Cd) batteries, nickel-metal hydride (NiMH) batteries, lithium-ion batteries and supercapacitors. Due to their low cost and reliable safety property, lead-acid batteries have been widely used for more than 150 years. However, lead-acid batteries have short cycling life and low power density. By comparison, Ni—Cd batteries have slightly improved power density and cycling life but with increased cost and toxicity. Comparing with the previous two types of batteries, NiMH batteries have significantly higher energy density, but their cycling life is still short and cost has been increased dramatically in the recent years due to the increased price of rare earth metals. Because of their high energy density, low self-discharge and long cycling life, lithium-ion batteries are so far the most widely used rechargeable batteries. However, the costs for lithium-ion batteries are high due to the need of scarce lithium and strictly controlled manufacturing process. And more importantly, since organic electrolyte is used in the lithium-ion battery, the safety property is poor, which is unfavorable for large-scale application such as EVs and grid-storage.
Compared with battery, supercapacitors can provide higher power density and longer cycling life, but their energy densities are too low to be used in large-scale storage. Although using organic electrolyte can provide improved energy density of supercapacitors, the cost is largely increased and the use of electrolyte also poses similar safety concern to lithium ion batteries.
There is therefore a great demand in developing safe and low cost electrochemical energy storage devices with significantly improved power density, energy density, and cycling life. Besides the too high cost, in the aspect of safety, currently used energy storage systems are problematic due to the use of highly flammable organic electrolytes, which cannot meet the safety requirement for applications. Aqueous-electrolyte-based energy storage devices, such as lead-acid batteries, Ni—Cd, and NiMH batteries, are non-flammable and safe in case of accident and other mis-operation situations. Therefore, improving the performance of aqueous-electrolyte-based energy storage devices can lead to highly safe, low-cost devices for transportation, stationary energy storage, and other broad spectrum of applications.
Among the aqueous-electrolyte-based systems, lead-acid batteries that are highly reliable and low cost are of particular commercial interest. To date, extensive efforts have been made to improve the performance of lead-acid batteries, such as making better electrodes with controlled composition and structure, using gel-like electrolyte and fibrous separation membranes. Despite such extensive efforts result in increased performance to some extent, overall it is thus far still difficult to fabricate lead-acid batteries with high enough power density and lifetime as required by many industrial applications.
In the recent years, lead-acid super-batteries were developed with significantly improved power performance and lifetime. This was mainly achieved by completely or partially replacing the traditional anode materials (Pb) and/or cathode materials (PbO2) with porous carbons. The prior arts in such super-batteries were described in a series of patents (KR1020060084441A, CA2680743, CA2680747, CN200910183503). Despite the improved power density and lifetime achieved, in comparison with the energy density of lead-acid batteries (40-50 Wh/kg), the cost is that the energy densities of such super-batteries are dramatically reduced (8-16 Wh/kg). The incorporation of carbon materials into electrodes inevitably leads to mismatched electrode potentials and low capacity.
Compared with the carbon material, metal oxide material can provide higher capacity. Therefore, an appropriate use of metal oxide can provide lead-acid super batteries with higher energy density. More studied oxides include manganese oxide, ruthenium oxide, iron oxide, et al nickel oxide, but there very limited oxides that are suitable for acidic electrolytes. Although ruthenium oxide can work in an acidic electrolyte, but its cost is extremely high and not suitable for large-scale industrial applications. Moreover, since its working voltage is above zero volts (compared to silver/silver chloride electrode), it is not suitable to construct lead-acid super batteries. Tungsten oxide material has excellent electrochemical stability in acidic solution, but so far there is very little research on its energy storage properties. Lee et al. (Chem Commun., 2011, 47, 1021-1023) reported the electrochemical properties of high-temperature-sintered tungsten oxide based on porous silica as hard template. Its working potential ranges from −0.2 to 0.8 V, but its capacity is low. Wang et al. (Adv. Energy Mater., 2012, 2, 1328-1332) reported tungsten oxide material grown at 1080° C. as a supercapacitor structure material, which has stable electrochemical properties in neutral sodium sulfate electrolytic solution. Lu et al (Carbon, 2014, 69, 287-293) reported the electrochemical properties of a simple tungsten oxide/carbon aerogel composite based on the lower temperature synthesis with single electrode, the operating voltage window also quite narrow (−0.3 to 0.5 volts), and therefore the capacitance is low. While these works reported the possibility of using tungsten oxide material as an energy storage material in acidic electrolytes, they did not establish an efficient full battery system. In addition, combining oxide material and lead material to construct an energy storage device has failed to report or proposed now.
Insofar as we are aware, no lead-acid storage devices formerly developed can provide high enough power and high energy density, as well as long enough lifetime, that are required by many industrial applications.
Disclosure
With the rapid development of modern industrialization and human civilization, human's demand in high efficiency, safe and low-cost energy storage technology continues to grow. Because lead-acid batteries have unique advantages, they are still based on the modern industry and have a great prospect in many applications.
However, improvements towards lead-acid battery materials, structure and technology are still unable to break through the bottleneck that limits its performance to improve, making it impossible to meet the needs in the field of large-scale energy storage and power supply.
Accordingly, the present technological invention focuses on the material itself to design and build a class of novel low-cost, high-performance super batteries based on lead-acid battery system. Their structures will be further described below. One aspect of the present invention is to provide a tungsten trioxide material for electrochemical energy storage and conversion devices, which is selected from one or more than one types of various tungsten trioxide crystal structures:
(a) the aforementioned various crystal structures of tungsten trioxide (WO3), comprising the monoclinic structure, triclinic structure, orthorhombic structure, cubic crystal structure, hexagonal structure, bi-continuous structure tungsten trioxide, and combinations of two or more from the various WO3 crystal structures;
(b) hydrous tungsten trioxides (WO3 nH2O) having said crystal structures of claim (a), where n values can range from 0 to 5, preferentially in the range of 0 to 2, more preferably in the range of 0-1;
(c) doped tungsten trioxides or hydrous tungsten trioxide with another element A (AxWO3 or AxWO3 nH2O) having said tungsten trioxide (WO3) of claim (a), or said hydrous tungsten trioxide (WO3 nH2O) of claim (b), wherein the doping element A may be selected from one or more of the following groups of elements: alkali metals, alkaline earth metals, transition metals, rare metals, of which x values may be in the range from 0 to 0.3, preferentially in the range of 0 to 0.1, more preferably in the range of 0 to 0.05, an alkali metal may be sodium, potassium, an alkaline earth metal may be calcium, strontium, transition metal may be titanium, zirconium, rare metal may be lanthanum, cerium;
(d) a mixture from one or more of the said tungsten trioxide (WO3) having various crystal structures of claim (a), said hydrous tungsten trioxides (WO3 nH2O) having various crystal structures of claim (b), and said element doped tungsten trioxides (AxWO3) or hydrous tungsten trioxide (AxWO3 nH2O) having various crystal structures of claim (c);
(e) a mixture or composite material consisting of one or more of the aforementioned tungsten materials of claim (a), (b), (c), (d), wherein tungsten material is tungsten trioxide (WO3), hydrous trioxide (WO3 nH2O), element-doped tungsten trioxide (AxWO3) or elements doped hydrous tungsten trioxide (AxWO3 nH2O), and additional tungsten-free material, wherein said tungsten-free material may be selected from the following materials: carbon materials, polymer materials, metal oxides or its salts, or ceramic materials, and the said carbon materials include, but are not limited to carbon black, onion structured carbon particles, activated carbon, mesoporous carbon, carbon nanotubes, carbon nanofiber, graphite, graphene, graphene oxide or various combinations thereof, the polymer materials include, but are not limited to, polyaniline, polypyrrole, polythiophene, poly (3,4-ethylenedioxythiophene), polystyrene, sulfonated polystyrene, or various combinations thereof, and the metals and their salts include, but are not limited to titanium, vanadium, chromium, zirconium, niobium, molybdenum, lead, bismuth or various combinations thereof, wherein the ceramic materials include, but are not limited to, zirconium oxide, silicon oxide, strontium oxide, aluminum oxide, or various combinations thereof;
(f) a mixture or composite material consisting of one or more of the aforementioned tungsten materials of claim (a), (b), (a), (d), wherein tungsten material is tungsten trioxide (WO3), hydrous trioxide (WO3 nH2O), element-doped tungsten trioxide (AxWO3) or elements doped hydrous tungsten trioxide (AxWO3 nH2O), and said mixture of composite of claim (e).
The wherein said tungsten trioxide material is a powdered material, the material particle size is around 50 μm or less, better choice of particle size is less than 20 μm, the optimal choice of particle size is less than 5 μm.
The wherein said electrochemical energy storage and conversion device is selected from the following: tungsten-carbon super battery, tungsten-tungsten super battery, tungsten-lead oxide super battery, tungsten/carbon-lead oxide hybrid super battery system.
The wherein said super batteries utilize an aqueous electrolyte solution, the preferred electrolyte is acidic aqueous system, better choice for the aqueous system electrolyte contains sulfuric acid.
The current collectors used the wherein said tungsten-carbon super battery, tungsten-tungsten super battery, tungsten-lead oxide super battery, tungsten/carbon-lead oxide hybrid super battery system may be a metal material, including but not limited to lead, chromium, titanium, tungsten, molybdenum, silver, ruthenium, palladium, platinum, iridium, gold and their alloys; a carbon material, a conductive polymer material or combination of said material, and the lead alloy grid used in commercial lead-acid batteries can also be used directly as an electrode current collector.
The lead oxide used in the wherein said tungsten-lead oxide super battery, tungsten/carbon-lead oxide hybrid super battery system can be the same as that used in commercial lead-acid batteries.
In conjunction with the following drawings, tungsten trioxide material and its applications of the present application will be further explained.